Process of making pure ammonium nitrate.



snares PATENT orri'cno'rro nirnnsenm or unnnmenu, Grammy", 'As'sIenon r0. THE FIRM" or a i:- v mm) a; co, m. a. 11., or unnnmenn, GERMANY.

"PitocEssIoF mam runn momma an 986,204. .Specific'ation'0!letterslatent- Patented Mar. 7,1911. in Drawing. Applicatlon fi IedFebrua?y-19,1' 9 10. sensual #544301,

To ullwhom'itflmy concern."

"I monium-nitrate is increased to such a de- 'Be it. known that}, O'i'ro Nronooun, a gr'ee that the latter cannot be used for the 55 citizen of the Swiss epublic, and residing production of safety-explosiyes. A

at-Uerdingemon-the-Rhine, Germany, have The objectof the present invention is to "5; invented a certain new and useful Process overcome this trouble, by preventing the siforsthe Preparation of Pure Ammonium Nimultaneous crystallization of the magnetrate from Ammonium Sulfate and Calcium -siumsulfate' with the ammoniuni-nitrate, 60 Nitrate .Containing'Magnesium, of which and, also permitting the separaterecovery the followi-n isaspecification. r of the magnesium-sulfate in a very simple "lechnica y pure ammoniummitrate has manner; For this purpose I proceed in such heretofore been obtaincd'by the neutralizaa way thatthe solution obtained by the tion of nitric acidwith ammonhu'recentlydouble decomposition of calcium-nitrate and 65 also by the double decomposition of sodiumammoniumssulfate contains, while being;

nitrate and ammonium sulfate set .forth evaporated up to the concentration necesin the specification of UJS. Patcnt,864,513.' sa'ry-for thecrystallization of the ammo- Since caleium-nitrate isproduced "on-"a n'iunnnitrate, an excess of 'calcium-nitratelarge scale by meansof electricity, this like "of preferably 1'*to 10% or thereahout over 70 wise affords a readily available material for the quantity theoretically required. In 7 the production ofammonuium-nitrate; The place of the' calcium-nitrate, strontiuinor decomposition of calcium-'nitrateby amino: barium-nitra'te may also be einployed.- In

7 mum-sulfate in RQREOHS'SOlhfiOD takesplace either'casethe magnesium salts remain coinaccording tothe equation: a pletely' in solution during the-concentration 75 v of the lye as'well as durin the coolin nec- Ca +0880 essary for the crystallizatibn of the aimnomum-nitrate." Even when the magnesium When working with dilute solutions, the salts are present in the mother-lye in relagypsum formed-separates out for the greater tively' lar 'ev quantities, (for example 10 so part;- the small portion remaining in soluparts M and even more to 100 parts tion is precipitated by concentrating the di- NH,NO theammonium-nitrate crystallute ammonium-nitrate solution, with the lizetl therefrom can be obtained free fromexception of a very small trace, correspond-' even a trace of magnesium compounds. Ining to its solubilityiin solutions of ammo asmuch as the iuother-lye of the amniouium- S5. mum-nitrate. The solution after'being sepnitrate crystallization'is again added to a mated from the gypsum and after being further quantity of equivalent parts of the sufficiently concentrated crystallizes only calcium-nitrate and aminouium-sulfate bea-mmonium-nitrate upon cooling, since the fore concentration, the excess of calciumgypsum, being more soluble in the cold, remtrateonce added either before decomposi- 90 mains in solution. Starting from pure cal tion, orduring concentration, is suilicient I cium-nitrate a very pure ammonium-nitrate "for enabling the process to be repeated until i 40 is therefore obtained in this way. The comthe mother-lye has to. be removed for the mercial calcium-nitrate however always separation of the magnesium-salts which contains; besides alumina and iron-oxid, will now be descrilnged.v Whenever the mag- 95 considerable quantities of magnesia and 'nesium Ysalts in the motherdye have been magnesium-nitrate as impurities. The magsufiiciently enriched, sufficient ammonium nesium compounds are dissolved during the sulfate is added to comfert not only the disdouble decomposition and are not 'removed solved calcium and magnesium salts into by concentration. If operating with equiva their sulfates, but that also an excess ofl'g w lent quantities of the two 'saltsor with an ammoniumsulfate (preferably from '1 to excess of sulfate of ammonia, they are upon 10% of the ammonium-nitratepresent) is cooling the concentrated solution, precipicontained in the solution. The magnesiums tated for the greater part, simultaneously sulfate or its double salt with ammoniumwith the ammonium-nitrate with the result sulfate thus formed is for the most part that the incombustible residue 'in the amcrystallized out from the hot solutionand separated,

of the requisite excess of nitrate o ficalciunr.

'In order to avoid the evaporation of large quantities of water the solutions of the salts are preferably kept near to their point oi saturation. In operating under the process,

the Water resulting from leaching the gypsum is used instead of fresh water for dissolving the two salts. The process can of course also be effected by adding one of the salts in'the solid state to the solution of the other salt. I

'As an example of carrying out the invention, the following proportions give satis- .or of another alkaline earth is returned to} the concentrating vessel.

factory results: 100 parts of calcium-nitrate containing 75% Ca( l\ O .dissolved in :20 parts of hot Water are added to the hot solution of partsof sulfate of ammonia containing 2574:NI-I in 70 parts of water. After removing the gypsum the solution is concentrated till it contains only 13 parts of water. After removing the hot solution from the gypsum precipitatedj during concentration the former is cooled to 2010 About 50 parts of nitrate of ammonia crystallize out and about 20 parts rcmain .in the mother-lye. To the latter are then added 5 parts of sulfate ofa'mnionia, andaftcr'sepzn rating from the precipitated gypsum and double salt of magnesium-sulfate Witl1sul fate-of ammonia the solution is used again in the process.

I claim as my invention:

1. The process of manufacturing anunoniunrnitrate from ammoniuni-sulfate and alkaline earth nitrate containing magnesium,- which consists in ctt'ccting double decomposition in the presence of an excess of the nitrate employed. removing the sulfate formed from the solution and then seppure.-

a 'ating the ammonium-nitrate by crystalli-- zation, whereby said ammoniuni-nitrate is obtained free from magnesium, ,substair t1a lly.asdescribed. 52. A process of manufacturing pure ammonium-nitrate from solutions of ammomum-sulfate and alkaline earth nitrate containing magnesium, \YlllCll consists in add- -in the nitrate in excess to the solution, re- 1 moving the sulfate formed from the solution, crysta'lhzmg, out the ammonium-nitrate, thereafter removing the magnesiunr from the mother-lyeby adding ammoniumconvert the magnesium salts as well as the into double sulfates andv crystallizing out the same, substantiallyas described. v

3. The process ,of manufacturing pure annnoniunrnitrate from ammonium-sulfate :t'alc, formed from the solution, and-then separating the ammonium-nitrate bycnystallization whereby said ammonium-nitrate is obtained free from magnesium, purifying the solution from the magnesium salts by adding an (Excess ofammonium-sulfate crysearth nitrate to the purified solution where by the latter maybe again employed for the production of ammonium-nitrate, as .described. I Y v 4-. A process of manufacturing pure ammonium-nitrate from solutions of ammo-.

tainin magnesium. which consists in adding the nitrate in excess to the solution,

after renaming the sulfate formed fro'nrthe sol u tion. repeating the process until themag+ tallizcd out. and then purifying the mother lye by adding ammonium-sulfate in more than sufl'icient quantity to convert the magnesium salts as well as the alkaline earth salts into their sulfatesor into double sulfates and 'crvstallizing. out the same-subs stantiallv as described.

ninm-nitrale containing magnesium. the ad dition of an excess of alkaline earth nitrate to the solution-before crystallizatlon of the,

salts present as impurities are retained in tallizes out, substantiallyar described. I In testimony whereof I have signedmy alkaline earth salts into their sulfates or and. alkaline earth .nitrate containing mag- (lOk'UllllH)Slil()ll in the presence of an excess. of the nitrate employed, removing the sulnosimn salts are present in such quantity" that pure ammonium-nitrate cannot be crys-f 5. In the process of obtaining pure a1nmomma-nitrate. from a solution of ammoannnonium-nitrate, whereb the magnesium sulfate in more thaii-suflicient quantity to tallizing'outnnd removing the magnesium salt and adding an excess of thealkaline nium-sulfate and alkaline earth nitrate con:

crystallizingout the ammonium-nitrate no I solution, while the ammoniunbnitrate crysname to this specification, in the presence of 

